IPAC2011 - List of Authors (Uvarov, V.L.)

Paper	Title	Page
MOPS040	Intra-Bunch Energy Spread of Electrons in Powerful RF Linacs for Nuclear Physics Research*	691
	V.V. Mytrochenko, M.I. Ayzatskiy, V.A. Kushnir, A. Opanasenko, S.A. Perezhogin, V.L. Uvarov NSC/KIPT, Kharkov, Ukraine
	Funding: Ukrainian State program of fundamental and applied studies on the use of nuclear materials, nuclear and radiation technologies in the fields of economics (YaMRT project No. 826/35) There are some particles in RF electron linacs with energy that may be significantly different from that of particles within a core of the bunch. Loss of these particles at average beam power of tens of kilowatts can cause radiation and thermal problems. Filtration of such particles during the initial stage of acceleration, at energies below the threshold of photonuclear reactions, is important. The paper analyzes several ways to perform such type of filtration in the injector part of a powerful electron linac using a RF chopper or magnetic systems.

THPS083	Two-channel Mode of Mo-99 Production at an Electron Accelerator	3627
	V.L. Uvarov, A.N. Dovbnya, V.V. Mytrochenko, V.I. Nikiforov, S.A. Perezhogin, V.A. Shevchenko, B.I. Shramenko, A.Eh. Tenishev, A.V. Torgovkin NSC/KIPT, Kharkov, Ukraine
	High-energy bremsstrahlung is the main source of isotopic target activation at an electron accelerator. The photoneutrons concurrently generated are generally considered as a background radiation. At the same time, the natural materials entering into photonuclear targets sometimes comprise a mixture of stable isotopes, the atomic-number difference of which equals 2. Thus, if the desired isotope has an intermediate mass, then at certain conditions, it can be produced on two target nuclei at once, via (γ,n) and (n,γ) channels. As an example, we investigate the possibility of increasing the yield of 99Mo by means of its simultaneous production from 100Mo(γ,n)99Mo and 98Mo(n,γ)99Mo reactions. The method and the device have been developed to provide measurements of the 99Mo yield from the natural molybdenum target as it is placed inside the neutron moderator and without the latter. Experiments were performed at the NSC KIPT accelerator LU-40m at electron energies ranging from 30 to 60 MeV. It is demonstrated that the use of the moderator gives nearly a 30% increase in the 99Mo yield. The experimental results are in good agreement with the computer simulation data.

THPS084	Modification of the PENELOPE Transport System for HS Simulation of Isotope Production Mode	3630
	V.L. Uvarov, V.I. Nikiforov NSC/KIPT, Kharkov, Ukraine
	A method has been developed for high-speed computing the photonuclear isotope yield along with the absorbed radiation power in exit devices of electron accelerator. The technique involves a step-by-step calculation of isotope microyield along the photon trajectories. The approach has been realized in the computer programs based on the PENELOPE system of -2001, -2006 and -2008 versions. For their benchmarking, use has been made of the experimental data on activity distributions of the 67Cu produced from 68Zn(γ,p)67Cu reaction in thick zinc targets. The results of simulation using the PENELOPE-2006 and -2008 codes are in excellent agreement with all experimental data. At the same time, the PENELOPE-2001 computations give good agreement with the experimental results for target activation by the electron beam, but systematically underestimate (~15%) in case of the target exposed to bremsstrahlung. The proposed technique provides a ~ 10⁴ times higher computation speed as compared with the direct Monte Carlo simulation of photonuclear events and that speed is independent of the reaction cross section.

Paper

Title

Page

Intra-Bunch Energy Spread of Electrons in Powerful RF Linacs for Nuclear Physics Research*

691

V.V. Mytrochenko, M.I. Ayzatskiy, V.A. Kushnir, A. Opanasenko, S.A. Perezhogin, V.L. Uvarov
NSC/KIPT, Kharkov, Ukraine

Funding: Ukrainian State program of fundamental and applied studies on the use of nuclear materials, nuclear and radiation technologies in the fields of economics (YaMRT project No. 826/35)
There are some particles in RF electron linacs with energy that may be significantly different from that of particles within a core of the bunch. Loss of these particles at average beam power of tens of kilowatts can cause radiation and thermal problems. Filtration of such particles during the initial stage of acceleration, at energies below the threshold of photonuclear reactions, is important. The paper analyzes several ways to perform such type of filtration in the injector part of a powerful electron linac using a RF chopper or magnetic systems.

THPS083

Two-channel Mode of Mo-99 Production at an Electron Accelerator

3627

V.L. Uvarov, A.N. Dovbnya, V.V. Mytrochenko, V.I. Nikiforov, S.A. Perezhogin, V.A. Shevchenko, B.I. Shramenko, A.Eh. Tenishev, A.V. Torgovkin
NSC/KIPT, Kharkov, Ukraine

High-energy bremsstrahlung is the main source of isotopic target activation at an electron accelerator. The photoneutrons concurrently generated are generally considered as a background radiation. At the same time, the natural materials entering into photonuclear targets sometimes comprise a mixture of stable isotopes, the atomic-number difference of which equals 2. Thus, if the desired isotope has an intermediate mass, then at certain conditions, it can be produced on two target nuclei at once, via (γ,n) and (n,γ) channels. As an example, we investigate the possibility of increasing the yield of 99Mo by means of its simultaneous production from 100Mo(γ,n)99Mo and 98Mo(n,γ)99Mo reactions. The method and the device have been developed to provide measurements of the 99Mo yield from the natural molybdenum target as it is placed inside the neutron moderator and without the latter. Experiments were performed at the NSC KIPT accelerator LU-40m at electron energies ranging from 30 to 60 MeV. It is demonstrated that the use of the moderator gives nearly a 30% increase in the 99Mo yield. The experimental results are in good agreement with the computer simulation data.

THPS084

Modification of the PENELOPE Transport System for HS Simulation of Isotope Production Mode

3630

V.L. Uvarov, V.I. Nikiforov
NSC/KIPT, Kharkov, Ukraine

A method has been developed for high-speed computing the photonuclear isotope yield along with the absorbed radiation power in exit devices of electron accelerator. The technique involves a step-by-step calculation of isotope microyield along the photon trajectories. The approach has been realized in the computer programs based on the PENELOPE system of -2001, -2006 and -2008 versions. For their benchmarking, use has been made of the experimental data on activity distributions of the 67Cu produced from 68Zn(γ,p)67Cu reaction in thick zinc targets. The results of simulation using the PENELOPE-2006 and -2008 codes are in excellent agreement with all experimental data. At the same time, the PENELOPE-2001 computations give good agreement with the experimental results for target activation by the electron beam, but systematically underestimate (~15%) in case of the target exposed to bremsstrahlung. The proposed technique provides a ~ 10⁴ times higher computation speed as compared with the direct Monte Carlo simulation of photonuclear events and that speed is independent of the reaction cross section.